Building a PC

Tareq - 8GB RAM doesn't make much sense, that'll be either 2*4GB or 4*2GB, either way, a bad choice for you. You should be getting 8GB sticks, and ideally using at a bare minimum 2, but better still, 3 or 4. As your X79 is a 4 channel system.

The Graphics card doesn't seem like a good option either, I would suggest an Nvidia 660 minimum for what you've been talking about. The 630 mentioned in this thread would be a poor performer even with 4GB memory - which is a little much honestly. If you're looking to keep the cost down, but get something useful, I suggest the 660 with 2GB.